1. Field
Example embodiments relate to a photodiode.
2. Description of the Related Art
An organic photodiode is used in smaller photoelectric applications instead of a silicon photodiode because the organic photodiode includes organic materials that have a higher absorption coefficient and selective wavelength absorption. Thus, the size of the organic photodiode may be more easily reduced.
However, the organic photodiode may have external quantum efficiency for visible light lower than the silicon photodiode and may have higher dark current due to impurity in the organic materials. The increase of the dark current may cause higher current leakage, and the higher current leakage may decrease sensitivity of the photodiode and the accuracy of the external quantum efficiency that can be calculated from the photo current during light reaction.
A buffer layer may be added between an anode and a photoelectric layer of the photodiode in order to reduce the dark current of the organic photodiode. However, the degree of the dark current reduction may not be sufficient.